Marine Dictionary & Glossary of Boating Terms

power output

Similar Terms: RMS, PTP, P-T-P, peak to peak

Fishfinders/Sonars: the power output is the amount of sound energy emitted into the water by the transmitter. Power output is quantified using either RMS (Root Mean Square) or P-T-P (Peak-to-Peak) measurements. Either method is acceptable, but when comparing power outputs, you must compare like with like; because P-T-P numbers are 8 times higher than RMS numbers.

Higher power output allows a higher penetration of sonar signal through weeds and thermoclines, reaching greater depths and allowing better operation in noisy environments. However, the traditional way of thinking was that higher power output meant a better fishfinder, but with the introduction of broadband transmitters using power more efficiently and alternating and spectrum scanning, the equation is no longer that simple.